<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .green{
            color: green;
        }
        .big{
            font-size: 100px;
        }
    </style>
</head>
<body>
    <div id="app">
        <div :class="className" @click="className.green = !className.green">老付</div>
    </div>
</body>
<script src="./js/vue.js"></script>
<script>
    Vue.config.productionTip = false;

    var vm = new Vue({
        el:"#app",
        data:{
            // className:"green big"
            className:{
                green:true,
                big:true
            }
            // className:["green",{big:true}]

        },
        methods:{
           /* fn(){
                this.className.green = !this.className.green
            }*/
        }
    })
</script>
</html>